Thermal solution for drive systems such as hard disk drives and digital versatile discs

ABSTRACT

A drive system including: a printed circuit board; a first integrated circuit mounted onto the printed circuit board; a drive assembly case that is connected to the printed circuit board; and a first thermal interface material thermally coupled between i) the printed circuit board and ii) the drive assembly case. Thermal energy generated by the first integrated circuit is dissipatable by the drive assembly case through the first interface material.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present disclosure is a continuation of U.S. application Ser. No.12/842,452 (now U.S. Pat. No. 7,957,094), filed on Jul. 23, 2010, whichis a divisional of U.S. application Ser. No. 11/495,295 (now U.S. Pat.No. 7,764,462), filed Jul. 28, 2006, which claims priority under 35U.S.C §119(e) to U.S. Provisional Application No. 60/759,164, filed Jan.13, 2006.

FIELD

The present disclosure relates to hard disk drives (HDD).

BACKGROUND

Electronic devices such as computers, laptops, personal video recorders(PVRs), MP3 players, game consoles, set-first boxes, digital cameras,and other electronic devices often need to store a large amount of data.Storage devices such as hard disk drives (HDDs) and digital versatilediscs (DVDs) may be used to meet these storage requirements. As the sizeof these devices decreases, heat dissipation has become moreproblematic.

Referring now to FIG. 1A, hard disk drive (HDD) 10 includes a hard driveassembly (HDA) printed circuit board assembly (PCBA) 14. A buffer module18 stores data that is associated with control of the HDD 10. The buffermodule 18 may employ SDRAM or other types of low latency memory. Aprocessor 22 that is arranged on the HDA PCBA 14 performs processingthat is related to the operation of the HDD 10. A hard disk controlmodule (HDC) 26 communicates with an input/output interface 24 and witha spindle/voice coil motor (VCM) driver module 30 and/or a read/writechannel module 34.

During write operation, read/write channel module 34 encodes the data tobe written via a read/write device 59, as described in detailhereinbelow. The read/write channel module 34 processes the signal forreliability and may include, for example, error correction coding (ECC),run length limited coding (RLL), and the like. During read operation,the read/write channel module 34 converts an analog output of theread/write device 59 to a digital signal. The converted signal is thendetected and decoded by known techniques to recover the data written onthe HDD.

As can be appreciated, one or more of the functional blocks of the HDAPCBA 14 may be implemented by a single integrated circuit (IC) or chip.For example, a first integrated circuit 1C-1 may include the buffermodule 18 and the processor 22. A second integrated circuit 1C-2 mayimplement the HDC module 26, the spindle VCM module 30, the read writechannel module 34 and/or the I/O interface 24. Still other componentcombinations may be implemented as integrated circuit(s). For example,the processor 22 and the HDC module 26 may be implemented by a singleintegrated circuit. The spindle/VCM driver module 30 and/or theread/write channel module 34 may also be implemented by the sameintegrated circuit as the processor 22 and/or the HDC module 26.

A hard drive assembly (HDA) case 50 provides a housing for one or morehard drive platters 52, which include a magnetic coating that storesmagnetic fields. The platters 52 are rotated by a spindle motor 54.Generally the spindle motor 54 rotates the hard drive platter 52 at afixed speed during the read/write operations. One or more read/writearms 58 move relative to the platters 52 to read and/or write datato/from the hard drive platters 52. The spindle/VCM driver module 30controls the spindle motor 54, which rotates the platter 52. Thespindle/VCM driver module 30 also generates control signals thatposition the read/write arm 58, for example using a voice coil actuator,a stepper motor or any other suitable actuator.

The read/write device 59 is located near a distal end of the read/writearm 58. The read/write device 59 includes a write element such as aninductor that generates a magnetic field. The read/write device 59 alsoincludes a read element (such as a magneto-resistive (MR) element) thatsenses the magnetic field on the platter 52. A preamp module 60amplifies analog read/write signals. When reading data, the preampmodule 60 amplifies low level signals from the read element and outputsthe amplified signal to the read/write channel device. While writingdata, a write current is generated which flows through the write elementof the read/write device 59 is switched to produce a magnetic fieldhaving a positive or negative polarity. The positive or negativepolarity is stored by the hard drive platter 52 and is used to representdata.

Referring now to FIG. 1B, an exemplary DVD system 61. A DVD PCBA 62includes a buffer 64 that stores read data, write data and/or volatilecontrol code that is associated the control of the DVD system 61. Thebuffer 64 may employ volatile memory such as SDRAM or other types of lowlatency memory. Nonvolatile memory 66 such as flash memory can also beused for critical data such as data relating to DVD write formats and/orother nonvolatile control code. A processor 68 arranged on the DVD PCBA62 performs data and/or control processing that is related to theoperation of the DVD system 61. The processor 68 also performs decodingof copy protection and/or compression/decompression as needed. A DVDcontrol module 70 communicates with an input/output interface 72 andwith a spindle/feed motor (FM) driver 74 and/or a read/write channelmodule 76. The DVD control module 70 coordinates control of thespindle/FM driver 74, the read/write channel module 76 and the processor68 and data input/output via the interface 72.

During write operations, the read/write channel module 76 encodes thedata to be written by an optical read/write (ORW) or optical read only(OR) device 78 to the DVD platter. The read/write channel module 76processes the signals for reliability and may apply, for example, ECC,RLL, and the like. During read operations, the read/write channel module76 converts an analog output of the ORW or OR device 78 to a digitalsignal. The converted signal is then detected and decoded by knowntechniques to recover the data that was written on the DVD.

A DVD assembly (DVDA) 82 includes a DVD medium 84 that stores dataoptically. The medium 84 is rotated by a spindle motor that isschematically shown at 86. The spindle motor 86 rotates the DVD medium84 at a controlled and/or variable speed during the read/writeoperations. The ORW or OR device 78 moves relative to the DVD medium 84to read and/or write data to/from the DVD medium 84. The ORW or ORdevice 78 typically includes a laser and an optical sensor.

For DVD read/write and DVD read only systems, the laser is directed attracks on the DVD that contain lands and pits during read operations.The optical sensor senses reflections caused by the lands/pits. In someDVD read/write (RW) applications, a laser may also be used to heat a dielayer on the DVD platter during write operations. If the die is heatedto one temperature, the die is transparent and represents one binarydigital value. If the die is heated to another temperature, the die isopaque and represents the other binary digital value. Other techniquesfor writing DVDs may be employed.

The spindle/FM driver 74 controls the spindle motor 80, whichcontrollably rotates the DVD medium 84. The spindle/FM driver 74 alsogenerates control signals that position the feed motor 90, for exampleusing a voice coil actuator, a stepper motor or any other suitableactuator. The feed motor 90 typically moves the ORW or OR device 78radially relative to the DVD medium 84. A laser driver 92 generates alaser drive signal based on an output of the read/write channel module76. The DVDA 82 includes a preamp circuit 93 that amplifies analog readsignals. When reading data, the preamp circuit 93 amplifies low levelsignals from the ORW or OR device and outputs the amplified signal tothe read/write channel module device 76.

The DVD system 61 may further include a codec module 94 that encodesand/or decodes video such as any of the MPEG formats. A scrambler 97 maybe used to perform data scrambling. Audio and/or video digital signalprocessors and/or modules 96 and 95, respectively, perform audio and/orvideo signal processing, respectively.

SUMMARY

A drive system including: a printed circuit board; a first integratedcircuit mounted onto the printed circuit board; a drive assembly casethat is connected to the printed circuit board; and a first thermalinterface material thermally coupled between i) the printed circuitboard and ii) the drive assembly case. Thermal energy generated by thefirst integrated circuit is dissipatable by the drive assembly casethrough the first interface material.

Further areas of applicability of the present disclosure will becomeapparent from the detailed description provided hereinafter. It shouldbe understood that the detailed description and specific examples, whileindicating the preferred embodiment of the disclosure, are intended forpurposes of illustration only and are not intended to limit the scope ofthe disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1A is a functional block diagram of an exemplary hard disk driveaccording to the prior art;

FIG. 1B is a functional block diagram of an exemplary digital versatiledisc (DVD) according to the prior art;

FIG. 2A illustrates a first drive system that is thermally coupled to adrive assembly case according to the present disclosure;

FIG. 2B illustrates the first drive system with an integrated circuit indirect physical contact with the drive assembly case;

FIG. 3 illustrates a second drive system that is thermally coupled to adrive assembly case according to the present disclosure;

FIG. 4 illustrates a third drive system that is thermally coupled to adrive assembly case according to the present disclosure;

FIG. 5 illustrates a fourth drive system that is thermally coupled to adrive assembly case according to the present disclosure;

FIG. 6A is a functional block diagram of a high definition television;

FIG. 6B is a functional block diagram of a vehicle control system;

FIG. 6C is a functional block diagram of a cellular phone;

FIG. 6D is a functional block diagram of a set top box; and

FIG. 6E is a functional block diagram of a media player.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is in no wayintended to limit the disclosure, its application, or uses. For purposesof clarity, the same reference numbers will be used in the drawings toidentify similar elements. As used herein, the term module, circuitand/or device refers to an Application Specific Integrated Circuit(ASIC), an electronic circuit, a processor (shared, dedicated, or group)and memory that execute one or more software or firmware programs, acombinational logic circuit, and/or other suitable components thatprovide the described functionality. As used herein, the phrase at leastone of A, B, and C should be construed to mean a logical (A or B or C),using a non-exclusive logical or. It should be understood that stepswithin a method may be executed in different order without altering theprinciples of the present disclosure.

The present disclosure relates to a low cost thermal solution fordissipating heat when high power integrated circuits (ICs) are used indrive systems. For example, the present invention may be used in harddisk drive (HDD) and digital versatile disc (DVD) systems. The HDDincludes a hard disk assembly (HDA) and a HDD printed circuit boardassembly (HDD PCBA) with one or more Integrated Circuits (ICs) and/orother electronics components mounted thereon. Some types of HDDs includean external case that is connected to the HDD PCB. While the certainportions of the present disclosure relate to HDD systems, the presentdisclosure can also be used to dissipate heat within DVD systems.

The ICs tend to generate a lot of heat due to high data flow speeds ofthe HDD or DVD and integration of more functions and features. As theform factor of the HDD or DVD becomes smaller, the PCB also becomessmaller. Dissipating heat generated by the IC or ICs of the PCB becomesmore challenging. According to the present disclosure, the driveassembly case can be used as a thermal heatsink by making the surface ofone or more ICs directly contact the drive assembly case and/or using athermal interface material to allow the thermal contact between the ICor ICs and the drive assembly case.

Referring now to FIGS. 2A and 2B, the drive assembly case can be used asa thermal heatsink by making the printed circuit board (PCB) contact thedrive assembly case through a thermal interface material. Moreparticularly, in FIG. 2A a PCB 100 includes an outer side 101 and aninner side 102. First and second integrated circuits (ICs) 104 and 108and/or other components 112 are mounted on the outer and/or inner sides101 and 102 of the PCB 100.

A drive assembly case 118 is connected to the inner side 102 of the PCB100. A second side of the IC 108 includes a thermal interface material120 that is located between the IC 108 and the drive assembly case 118.The terminal interface material 120 thermally couples the second side ofthe IC 108 to the drive assembly case 118. As a result, heat generatedby the IC 108 is dissipated by the relatively large surface area of thedrive assembly case 118. In FIG. 2B, the IC 108 directly contacts thedrive assembly case 118.

Referring now to FIG. 3, additional thermal vias can be added at thecontact area of PCB to further improve thermal performance. One side 149of a PCB 150 includes first and second ICs 154 and 158 and/or othercomponents 155. The PCB 150 includes vias 160 that extend from the oneside 149 of the PCB 150 to another side 151 thereof. A thermal interfacematerial 164 thermally couples opposite ends of the vias 160 of the PCB150 to a drive assembly case 166. Other components of the HDD or DVD maybe connected to either side of the PCB 150 as shown. Direct contactbetween the vias and the drive assembly case can also be used.

Referring now to FIG. 4, for HDDs or DVDs with the external cases overthe PCB, the external case can be used as a thermal heatsink by makingthe surface of one or more ICs directly contact the external case and/orthrough a thermal interface material. A PCB 200 includes first andsecond ICs 202 and 204 and/or other components 206 mounted thereon. ThePCB 200 is mounted to the drive assembly case 210 and covered by anexternal cover 212. The IC 204 includes an outer surface 219 thatcontacts a thermal interface material 220. The thermal interfacematerial 220, in turn, contacts the external cover 212.

Referring now to FIG. 5, more thermal vias can be added at the contactarea of PCB to further improve the thermal performance. The PCB 200includes vias 230 that extend through and/or provide a thermal paththrough the PCB 200. A thermal interface material 240 provides a thermalpath between the vias and the drive assembly case 210.

As can be appreciated, while only one IC is shown in contact with thedrive assembly case in FIGS. 2-5, the solution can be applied to two ormore ICs on the PCB. Furthermore, while FIG. 2B shows direct physicalcontact between the drive assembly case and the IC, FIGS. 3-5 may alsobe arranged in direct physical contact as well. Furthermore, embodimentsmay include ICs in direct and/or indirect contact via the thermalinterface material.

Suitable examples of thermal interface materials include thermalconductive adhesive tape, thermal conductive elastomer, thermalconductive compound and thermal grease although other thermal interfacematerials can be used.

Referring now to FIG. 6A, the present invention can be implemented inmass data storage and/or a DVD of a high definition television (HDTV)420. The HDTV 420 receives HDTV input signals in either a wired orwireless format and generates HDTV output signals for a display 426. Insome implementations, signal processing circuit and/or control circuit422 and/or other circuits (not shown) of the HDTV 420 may process data,perform coding and/or encryption, perform calculations, format dataand/or perform any other type of HDTV processing that may be required.

The HDTV 420 may communicate with mass data storage 427 that stores datain a nonvolatile manner such as optical and/or magnetic storage devices.The HDD may be a mini HDD that includes one or more platters having adiameter that is smaller than approximately 1.8″. The HDTV 420 may beconnected to memory 428 such as RAM, ROM, low latency nonvolatile memorysuch as flash memory and/or other suitable electronic data storage. TheHDTV 420 also may support connections with a WLAN via a WLAN networkinterface 429.

Referring now to FIG. 6B, the present invention may implement and/or beimplemented in mass data storage of a vehicle control system and/or avehicle-based DVD. In some implementations, the present inventionimplement a powertrain control system 432 that receives inputs from oneor more sensors such as temperature sensors, pressure sensors,rotational sensors, airflow sensors and/or any other suitable sensorsand/or that generates one or more output control signals such as engineoperating parameters, transmission operating parameters, and/or othercontrol signals.

The present invention may also be implemented in other control systems440 of the vehicle 430. The control system 440 may likewise receivesignals from input sensors 442 and/or output control signals to one ormore output devices 444. In some implementations, the control system 440may be part of an anti-lock braking system (ABS), a navigation system, atelematics system, a vehicle telematics system, a lane departure system,an adaptive cruise control system, a vehicle entertainment system suchas a stereo, DVD, compact disc and the like. Still other implementationsare contemplated.

The powertrain control system 432 may communicate with mass data storage446 that stores data in a nonvolatile manner. The mass data storage 446may include optical and/or magnetic storage devices for example harddisk drives HDD and/or DVDs. The HDD may be a mini HDD that includes oneor more platters having a diameter that is smaller than approximately1.8″. The powertrain control system 432 may be connected to memory 447such as RAM, ROM, low latency nonvolatile memory such as flash memoryand/or other suitable electronic data storage. The powertrain controlsystem 432 also may support connections with a WLAN via a WLAN networkinterface 448. The control system 440 may also include mass datastorage, memory and/or a WLAN interface (all not shown).

Referring now to FIG. 6C, the present invention can be implemented inmass data storage and/or a DVD of a cellular phone 450 that may includea cellular antenna 451. In some implementations, the cellular phone 450includes a microphone 456, an audio output 458 such as a speaker and/oraudio output jack, a display 460 and/or an input device 462 such as akeypad, pointing device, voice actuation and/or other input device. Thesignal processing and/or control circuits 452 and/or other circuits (notshown) in the cellular phone 450 may process data, perform coding and/orencryption, perform calculations, format data and/or perform othercellular phone functions.

The cellular phone 450 may communicate with mass data storage 464 thatstores data in a nonvolatile manner such as optical and/or magneticstorage devices for example hard disk drives HDD and/or DVDs. The HDDmay be a mini HDD that includes one or more platters having a diameterthat is smaller than approximately 1.8″. The cellular phone 450 may beconnected to memory 466 such as RAM, ROM, low latency nonvolatile memorysuch as flash memory and/or other suitable electronic data storage. Thecellular phone 450 also may support connections with a WLAN via a WLANnetwork interface 468.

Referring now to FIG. 6D, the present invention can be implemented inmass data storage and/or a DVD of a set top box 480. The set top box 480receives signals from a source such as a broadband source and outputsstandard and/or high definition audio/video signals suitable for adisplay 488 such as a television and/or monitor and/or other videoand/or audio output devices. The signal processing and/or controlcircuits 484 and/or other circuits (not shown) of the set top box 480may process data, perform coding and/or encryption, performcalculations, format data and/or perform any other set top box function.

The set top box 480 may communicate with mass data storage 490 thatstores data in a nonvolatile manner. The mass data storage 490 mayinclude optical and/or magnetic storage devices for example hard diskdrives HDD and/or DVDs. The HDD may be a mini HDD that includes one ormore platters having a diameter that is smaller than approximately 1.8″.The set top box 480 may be connected to memory 494 such as RAM, ROM, lowlatency nonvolatile memory such as flash memory and/or other suitableelectronic data storage. The set top box 480 also may supportconnections with a WLAN via a WLAN network interface 496.

Referring now to FIG. 6E, the present invention can be implemented inmass data storage and/or a DVD of a media player 500. In someimplementations, the media player 500 includes a display 507 and/or auser input 508 such as a keypad, touchpad and the like. In someimplementations, the media player 500 may employ a graphical userinterface (GUI) that typically employs menus, drop down menus, iconsand/or a point-and-click interface via the display 507 and/or user input508. The media player 500 further includes an audio output 509 such as aspeaker and/or audio output jack. The signal processing and/or controlcircuits 504 and/or other circuits (not shown) of the media player 500may process data, perform coding and/or encryption, performcalculations, format data and/or perform any other media playerfunction.

The media player 500 may communicate with mass data storage 510 thatstores data such as compressed audio and/or video content in anonvolatile manner. In some implementations, the compressed audio filesinclude files that are compliant with MP3 format or other suitablecompressed audio and/or video formats. The mass data storage may includeoptical and/or magnetic storage devices for example hard disk drives HDDand/or DVDs. The HDD may be a mini HDD that includes one or moreplatters having a diameter that is smaller than approximately 1.8″. Themedia player 500 may be connected to memory 514 such as RAM, ROM, lowlatency nonvolatile memory such as flash memory and/or other suitableelectronic data storage. The media player 500 also may supportconnections with a WLAN via a WLAN network interface 516. Still otherimplementations in addition to those described above are contemplated.

Those skilled in the art can now appreciate from the foregoingdescription that the broad teachings of the disclosure can beimplemented in a variety of forms. Therefore, while this disclosureincludes particular examples, the true scope of the disclosure shouldnot be so limited since other modifications will become apparent to theskilled practitioner upon a study of the drawings, the specification andthe following claims.

1. A drive system comprising: a printed circuit board; a firstintegrated circuit mounted onto the printed circuit board; a driveassembly case that is connected to the printed circuit board; and afirst thermal interface material thermally coupled between i) theprinted circuit board and ii) the drive assembly case, wherein thermalenergy generated by the first integrated circuit is dissipatable by thedrive assembly case through the first interface material.
 2. The drivesystem of claim 1, further comprising: a platter; a read/write armconfigured to read data from and write data to the platter; and aspindle motor configured to rotate the platter, wherein each of theplatter, the a read/write arm, and the spindle motor are housed in thedrive assembly case.
 3. The drive system of claim 1, wherein the firstintegrated circuit comprises one or more of: a read/write channelmodule, a buffer module, a processor, a hard disk control module, and aspindle/voice coil motor.
 4. The drive system of claim 1, furthercomprising: a second integrated circuit mounted onto the printed circuitboard; and a second thermal interface material thermally coupled betweeni) the printed circuit board and ii) the drive assembly case, whereinthermal energy generated by the second integrated circuit isdissipatable by the drive assembly case through the second interfacematerial.
 5. The drive system of claim 1, further comprising a thermalvia in contact with each of the first integrated circuit and the firstthermal interface material, wherein the thermal energy generated by thefirst integrated circuit is dissipatable by the drive assembly casethrough i) the thermal via and ii) the first interface material.
 6. Astorage device comprising the drive system of claim
 1. 7. The storagedevice of claim 6, wherein the storage device is a hard disk drive. 8.The storage device of claim 6, wherein the storage device is a digitalversatile disc drive.
 9. An electronic device comprising the storagedevice of claim
 6. 10. The electronic device of claim 9, wherein theelectronic device comprises a device selected from the group consistingof a computer, a laptop, a personal video recorder, an MP3 player, agame console, and a digital camera.